| FWIW:
boom is a mid thing. In fact most bass tones are a mid thing cause it comprises about 90% of the audible bass signal from what I can tell. Next time you're around a biamped rig where you can cut frequencies below 1K off the top and 80 Hz above off the bottom listen and see what's left above and below - not much.
I'd look on harmony central reviews for your bass and see how well you their experiences line up with yours. If they don't, probably not the bass.
Boom typically is not desireable and unfortunately not hard to come by. Can't remember but if you do a net search you'll see sound engineer listings for typical frequencies that yield typical results - good and bad. Boom is a common negative one but you can usually bring it on in short order by simply boosting mids or bass till it shows, depends on the variables involved.
Big speakers in small sealed boxes (ala 15's in practice amps) usually have lots of it. | 
Pickups for Yamaha TRB1004 
